One of my su carbs has a stuck lifter pin. I've sprayed it with Blaster seveal times with no luck. What is my next step TO free it up without cracking the aluminum casting? All Help appreciated.
Woody in Miami
66 P1800
91 240
93 940 turbo wagon

Clean the exterior of your carbs with carb or engine cleaner and rinse. Remove the filter housing so you can see what your are doing and then remove the three cheese-head screws holding the dashpot cover on the carb (big dome thingy). If it won't come off easily then rotate it to break it free. DO NOT SMACK IT WITH ANYTHING, EVEN YOUR HAND!
The damper will still be in it and will drip a little oil so set it on a cloth.
Remove the piston and needle by lifting straight up. Also set on the cloth being careful of the relatively delicate needle (also damper tube is full of oil!).
NOW put PB blaster or whatever cleaner stuff you like on the (obviously) sticking up pin... it should have an e-clip on it so it may not seem to be getting cleaner.
Tap it down then work it up and down until it moves freely.
Reassemble. Careful of that needle! Use no goober schmuckum on the assembly or screws. Top-up the oil if it spilled or you drained it.

Mike!

Woody;

Remove (filter and) dashpots to gain access to the spring and mechanism from above...spraying it with solvent from above will surly free them up...the return springs are quite strong and these pins get pretty well stuck from lack of use...lubing with grease should keep them freed up for a loooong time...don't mix up front and rear dashpots on reassembly, unless want to do a jet centering job too (maybe).

Cheers

Maybe a little carb cleaner will help, perhaps assisted by at moderate
application of brute force.
--
George Downs, Bartlesville, Oklahoma, Central US

I'm used to the HF6 SU, but I'm not sure what a lifter pin is.

There is an HS series (HS6 on Volvos) and an HIF series (HIF6 on Volvos).
Both have lifter pins that lift the piston which changes the venturi size.
It is used to check the mixture. It is at the side of the main barrel and
sticks out at a slight angle. Both your Volvo manual and your SU manual
will show pictures of it in the section about mixture adjustment but may
call it by different names.
--
George Downs, Bartlesville, Oklahoma, Central US